In the known sand-blasting installations, a grate is disposed above the hall floor, below which several longitudinal conveyors push the sand dropping-down during sand-blasting in one direction by means of conveyor members, where they drop into a recess in the hall floor, in which a cross conveyor takes over the further transporting of the blasting sand. The cross conveyor pushes the blasting sand which has been pushed toward the same by the longitudinal conveyors, into a pit, from which a bucket-type mechanism conveys the sand upwardly and feeds the same to a preparation installation. Sand-blasting installations which are equipped with such a conveyor arrangement are able to operate continuously. The drives of the individual longitudinal conveyors and of the cross-conveyor operate individually by means of crank drives which impart to the foldable conveyor members a to-and-fro movement. The conveyor action results from the fact that the conveyor members, whose distance is smaller or equal to the stroke of the drive, assume a vertical position in the conveying direction and thus push the sand in front of them whereas during the return movement, they fold over and slide over the sand to be conveyed into the starting position. In a known construction, the conveyor members are formed by vertically arranged rigid rakes at which rubber flaps abut unilaterally. In the pushing direction corresponding to the conveying direction, the rubber flaps are pressed against the rakes. During the opposite movement (coasting movement), the rubber flaps give way and pass over the surface of the sand without taking the same along. The efficiency of this system is impaired by the rigid, non-retracting prongs of the rake. This conveyor installation requires structural change measures of the hall owing to the required level jumps. Furthermore, the rubber members are subjected to a very strong wear and have to be exchanged frequently, whereby a disassembly of screwed-together clamping members is required.